There is increasing evidence that saturated fats in the diet elevate serum cholesterol levels and may be at least one factor responsible for the high incidence of heart disease in this country. Consequently, the food industry has been directing much effort to develop new products and modify existing products to incorporate higher relative levels of polyunsaturated fats. However, because of their different physical and chemical properties, many problems are encountered in formulating commercially acceptable products of this type.
One of the problems encountered is the poor storage stability of the high polyunsaturated fats and products containing them. They are highly susceptible to oxidative rancidity. Accordingly, they must be treated in some manner to decrease this tendency.
A number of chemical additives have been suggested as antioxidents for polyunsaturated oils. Among these are the synthetic phenolic antioxidants, the most effective of which is tertiarybutyl hydroquinone (TBHQ). Others are butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). These compounds are, however, regulated by the government, and the limited usage presently permitted is always subject to change.
Recently, several workers (Kawasaki-shi,H.E. et al. U.S. Pat. No. 3,585,223) tested the antioxidant capabilities of several amino acids; and, on the basis of peroxide values, determined that cystine was the best. Other workers (Fujimaki, et al.; Agri. Biol. Chem., Vol. 33, No. 8, p. 1144-1151; 1969) suggest that when the amino acid methionine was heated in oil, the degradation produce 3-methyl-thiopropylamine is useful as an antioxidant. There is, however, a continuing need to provide suitable alternatives to these materials with comparable or superior effectiveness.